The guided-missile destroyer USS Nitze (DDG-94) was followed and harassed by four Iranian patrol boats on Tuesday in the Persian Gulf, defense officials confirmed to USNI News.

The destroyer was in the vicinity of the Strait of Hormuz when four Iranian Revolutionary Guard Corps Navy high-speed patrol boats came at the ship without responding to hails or warning flares fired from Nitze, according to a video of the incident provided to USNI News.

“This is USS Nitze reporting from the Southern Arabian Gulf,” said a voice on the video reporting the ship’s location and speed.

“We have visual contact with four Iranian… WPBs… Bridge to bridge COMMS were conducted but no response. Weapons uncovered… appears to be unsafe, unprofessional.”

While the voice is making the radio report, the four patrol boats speed in a serpentine formation toward Nitze with their deck weapons uncovered. Flares from the destroyer attempt to warn away the patrol boats as they close in on the ship.

Nitze’s crew attempted to hail the boats a dozen times, fired 10 warning flares at the patrol boats and blasted the ship’s whistle to sound a maritime danger signal to no apparent effect, a defense official confirmed to USNI News late Wednesday.

Two of the patrol boats came within 300 yards of the destroyer before slowing and breaking off their chase.

“The Nitze and U.S. Naval Forces Central Command (NAVCENT) assessed the interaction as unsafe and unprofessional due to the Iranian vessels not abiding by international law and maritime standards including the 1972 Convention on the International Regulations for Preventing Collisions at Sea (COLREGS) maritime ‘Rules of the Road’,” a defense official told USNI News.

“The Iranian high rate of closure on a Unites States ship operating in accordance with international law while transiting in international waters along with the disregard of multiple warning attempts created a dangerous, harassing situation that could have led to further escalation including additional defensive measures by Nitze.”